CIRCULAR OISTURBANCKS. 



129 



may become mixed with the blood and become entangled in the 

 cardiac valves, thus interfering with heart action (a'hurse was 

 destroyed in four minutes bv injectino- air into the iu-ular 

 vem). 



Location. — Embolism occurs most frequently in arteries and 

 in the portal circulatory system. \'enons emboli as a rule pass 

 to the right side of the heart and into the pulmonary arteries 

 where they lodge. Fragments of thrombi from intestinal veins 

 pass into the portal system and are lodged in the hepatic capil- 

 laries thus producing embolism. Thrombic fragments from 



Fis. S-1. — Embolism. Thf (.■niiji.lus lodg^*d al tin- pi.iint 



iii\isii.ia of an art-ry. 



the pulmonarv veins, bicuspia valve and semi-lunar \al\es pass 

 into the arota and through its various branches and terminals 

 as emboli and finallv they occlude the containing vessel and thus 

 produce embolism. Paradoxical eml)olism is the name applied 

 to the condition resulting from obstruction of an arter\- witli an 

 embolus derii,'ed from the venous system and which has passed 

 from the right side of the heart to the left through the foramen 

 ovale. 



